// crc32.h: Schnittstelle für die Klasse CRC32.
//
//////////////////////////////////////////////////////////////////////

#if !defined(_CRC32_H)
#define _CRC32_H

typedef unsigned long crc32l;

const long CRC32_NEGL = 0xffffffffLU;

#define IS_LITTLE_ENDIAN

#ifdef IS_LITTLE_ENDIAN
#define CRC32_INDEX(c) (c & 0xff)
#define CRC32_SHIFTED(c) (c >> 8)
#else
#define CRC32_INDEX(c) (c >> 24)
#define CRC32_SHIFTED(c) (c << 8)
#endif


class CRC32
{
public:
	CRC32();

	void Update(const unsigned char *input, unsigned int length);
	crc32l GetFinal();

	void UpdateByte(unsigned char b) {m_crc = m_tab[CRC32_INDEX(m_crc) ^ b] ^ CRC32_SHIFTED(m_crc);};
	unsigned char GetCrcByte(unsigned int i) const {return ((unsigned char *)&(m_crc))[i];};

	static char * GetFileCRCString(char * filename, char * path=0);
	static crc32l GetFileCRC(char * filename, char * path=0, int * size=0);
	static crc32l GetMemCRC(char * buf, int size);

	void TruncatedFinal(unsigned char *hash, unsigned int size);
	
private:
	void Reset() {m_crc = CRC32_NEGL;};
	
	static const crc32l m_tab[256];
	crc32l m_crc;
};

#endif // !defined(_CRC32_H)